mu4e-compose: rework mu4e-compose-goto-(bottom|top)

For backward compat.

mu4e/mu4e-compose.el

@@ -611,8 +611,13 @@ buffers; lets remap its faces so it uses the ones for mu4e."
     (define-key map (kbd "C-c C-u")  #'mu4e-update-mail-and-index)
     (define-key map (kbd "C-c ;")    #'mu4e-compose-context-switch)
 
-    (mu4e-keymap-set map "<remap> <beginning-of-buffer>" #'mu4e-compose-goto-top)
-    (mu4e-keymap-set map "<remap> <end-of-buffer>" #'mu4e-compose-goto-bottom)
+    ;; emacs 29
+    ;;(keymap-set map "<remap> <beginning-of-buffer>" #'mu4e-compose-goto-top)
+    ;;(keymap-set map "<remap> <end-of-buffer>" #'mu4e-compose-goto-bottom)
+    (define-key map (vector 'remap #'beginning-of-buffer)
+                #'mu4e-compose-goto-top)
+    (define-key map (vector 'remap #'end-of-buffer)
+                #'mu4e-compose-goto-bottom)
 
     ;; remove some unsupported commands... [remap ..]  does not work here
     ;; XXX remove from menu, too.

mu4e/mu4e-helpers.el

@@ -600,14 +600,5 @@ shorter keys in some cases where there are multiple bindings."
              (seq-map #'key-description
                       (where-is-internal cmd)))))
 
-(defun mu4e-keymap-set (keymap key definition)
-  "Set KEY to DEFINITION in KEYMAP.
-Temporary version, from Emacs 29."
-  (when (fboundp 'key-valid-p) (cl-assert (key-valid-p key)))
-  (when (stringp definition)
-    (when (or (not (fboundp 'key-valid-p)) (cl-assert (key-valid-p definition)))
-        (setq definition (key-parse definition))))
-  (define-key keymap (key-parse key) definition))
-
 (provide 'mu4e-helpers)
 ;;; mu4e-helpers.el ends here